1. Field of Invention
The present invention relates to a counter. More particularly, the present invention relates to a counter composed of at least one frequency divider.
2. Description of Related Art
Many computer systems, such as the power supply circuit of the white light emitting diode circuit and the power management circuit, use a counter for implementing their intended function. The power consumption of computer systems is important to system designers because it directly affects the working time of the computer system. Furthermore, because energy storage subsystems (e.g., batteries) are often bulky and heavy, power consumption indirectly affects the overall size and weight of the computer system.
In computer systems having counter circuits implementing a watchdog reset or a power management transition timer, the corresponding event is triggered if the corresponding counter reaches a predetermined value. For example, in a disk circuit, a counter circuit is reset by the periodic disk access. If there is no disk accesses over a given time interval, the counter is run down (or up) to a predetermined value thereby triggering a transition to another power management mode, e.g., standby mode.
Unfortunately, because the associated power dissipation and the area of the counter circuit are large, which limits the number of counters in the computer system, and some functions of the computer system can not be implemented as a result.
Therefore, there is a need for a new counter which can reduce the power consumption and the required circuit area.